How do I create a curve like Hoss' Hat?
You should begin with less edge loops. Also, use the Mirror modifier as the hat seems rather symmetrical. Now you could do it with some extrusions, but maybe it's better to keep concentric circle to have a better topology. So enable the Proportional Editing option, drag up some vertices and edges, then inwards. At the end, add a Solidify modifier to give thickness, and a Subdivision Surface to smooth it.